Legal personhood has expanded dramatically beyond traditional boundaries to include rivers, future generations, and potentially artificial intelligence and animals. Yet many such innovations fail, collapsing into symbolic gestures without practical effect. This book argues that these failures stem not only from fragmented approaches that privilege one dimension - environmental protection, governance efficiency, or social equity - while neglecting others, but also from treating legal personhood itself as a solution rather than as a regulatory tool requiring careful institutional design. Corporate personhood evolved through governance sophistication that often externalised environmental and social costs. Environmental personhood emerged from ecological imperatives but frequently faltered due to weak governance structures and contested legitimacy, as illustrated by contrasting New Zealand's successful Whanganui River framework (comprehensive governance, dedicated funding, and Maori tikanga integration) with India's failed river personhood orders (minimal resources, unclear authority, exclusionary framing). The book develops an integrated Environmental, Social, and Governance (ESG) framework establishing three interlocking criteria: environmental integrity, social equity, and governance feasibility. These function not as independent variables but as mutually constitutive requirements - environmental objectives require governance mechanisms and social legitimacy; governance arrangements require environmental purpose and social legitimation; social acceptance depends on environmental outcomes and governance processes. Through comparative analysis across multiple jurisdictions, the book shows how ESG can evaluate personhood regimes and, crucially, serve as a pre-recognition diagnostic for determining when governance should proceed through alternative legal architectures rather than through the creation of new legal persons. In doing so, it reframes personhood as an inst
